| 摘要 |
<p>PURPOSE:To extend line distance by providing a terminal device with a storage battery and a constant current circuit, and feeding the terminal device with the discharging current of the storage battery when the terminal device is in use. CONSTITUTION:When the terminal DTE is not in operation, the DC power source B1 in a main device MAIN supplies a current to the constant current circuit CI in the terminal device DTE through a feed line D-LINe. When the terminal device DTE starts operating, the storage battery B2 supplies electric power to an electric circuit LD as a load through a diode D. When the out-of- use time (t) of the terminal device DTE is much longer than the in-use time T, the set value I0 of the constant current circuit CI is put closer to a current In when the terminal is not in use, and the line between the main device MAIN and terminal device is extended greatly.</p> |
